Lastly Portable.net is developed mainly in Australia (where reverse engineering for compatibility is legal) , India (where there are no e-patents), New Zealand , Canada and only some bits in the US . Which cannot be said about Mono which is based right in USPTO's firing range.

Out of curiosity, what would happen if you wanted to run Portable.NET in the US or places where reverse engineering is illegal? Would it still be legal to run Portable.NET?